glog doesn't build with latest gflags due to namespacing

[GoogleCodeExporter]

What steps will reproduce the problem?
1. build gflags w/ defaults
2. configure glog with --with-gflags set
3. build glog

What is the expected output? What do you see instead?
All of the *_unittest.cc files fail to build because they expect 
ParseCommandLineFlags and FlagSaver to be in the global namespace (or pulled in 
via "using namespace").  However, gflags has changed it's namespace from 
"google" to "gflags", so the "using namespace GOOGLE_NAMESPACE" statements 
don't pull ParseCommandLineFlags and FlagSaver in like they should.

What version of the product are you using? On what operating system?
glog r142

Please provide any additional information below.

Original issue reported on code.google.com by and...@spacemonkey.com on 5 May 2014 at 4:50